1) The concept of gravity was famously described by Sir Isaac Newton after an apple fell on his head.

2) Sir Elton John, born Reginald Kenneth Dwight, is an English singer, songwriter, and pianist. With a career spanning over five decades, he is one of the best-selling music artists in the world and has received numerous awards and accolades for his contributions to music.

3) In Norse mythology, the Valkyries are divine maidens who serve Odin, the chief god. They are responsible for selecting warriors worthy of entering Valhalla and escorting them to the afterlife. They are often depicted as powerful and beautiful figures, riding winged horses and wielding spears.

4) The blue whale is the largest animal to have ever existed, with an average length of about 82 feet (25 meters).